TALLAHASSEE, Fla. -- Nearly half of Florida's high schools received an A grade for the 2011-12 school year.

Preliminary grades released by the Florida Department of Education on Friday show 47 percent of high schools earned an A and 31 percent a B. The number of schools receiving an A jumped 16 percent.

Three schools were given an F, down from six in 2010-11.

The increase in the number of schools receiving an A came despite use of a more rigorous graduation rate and standards. The state Board of Education however also approved measures to ease the transition in the 2011-12 school year grading.

The states grades its high schools based on student performance on the Florida Comprehensive Assessment Test as well as indicators of college readiness and participation in advanced classes.